Linear motors are a form of electric motors in which electrical energy is used to drive a motor component in one or more linear directions. For example, many existing linear motors generate a magnetic field which influences one or more permanent magnets to move in the linear directions.
Alternatively, the permanent magnets can be fixed in a certain position and the component that generates the magnetic field (e.g. an armature including windings) can move as a result of the magnetic forces.
However, both of the above noted designs require the linear motor to include one or more permanent magnets, which are relatively expensive components. For example, various industrial processes must be performed to create and shape permanent magnets of sufficient strength and quality for use within a linear motor.
Further, certain permanent magnets can be formed from rare earth elements or other materials of limited global quantity or commercial availability. As such, high quality permanent magnets can significantly contribute to the cost associated with producing a linear motor.
Therefore, linear motors that do not rely upon permanent magnets for operation are desirable.